Regmatodon is characterized by ascending to erect distal stems and branches, somewhat asymmetric, ovate-short lanceolate leaves, short acuminate apex, entire margins, a strong costa ca. 1/2-2/3 lamina length, often weakly forked above, smooth and thick-walled laminal cells, rhomboidal to oblong, somewhat obliquely arranged median cells, and subquadrate to short rectangular marginal and basal cells. The peristome aids most in distinguishing this taxon; the exostome is ca. 1/2 or less endostome length, and the endostomial basal membrane is low. The genus may be confused with the Leskeaceae which it was previously placed with, but differs by the peristomial differences previously discussed. Regmatodon contains two species with a pantropical distribution, only the species given below is present in the Neotropics (Eakin, 1998). The more familiar name, R. polycarpus has been shown to predate R. orthostegius by only a few months (Eakin & Allen 1999).